Project Summary/Abstract Research: Invasive lobular carcinoma (ILC) is a unique histological subtype of breast cancer that has chronically been understudied. The long-term goal of the proposed research project is to credential non-canonical FADD signaling as a genetic driver of ILC. Based on its high expression/amplification in human ILC cell lines, tumors and metastatic samples and its association with poor survival, I hypothesize that FADD is a key mediator of ILC disease progression and a novel therapeutic target to improve patient outcomes. I will test this hypothesis through the following specific aims: Aim 1: Investigate the functional role of non-canonical FADD in ILC biology In contrast to its death-related cytoplasmic functions, nuclear FADD plays a non-canonical pro-survival role. This aim will couple RNAi and CRISPR loss-of-function approaches with viral overexpression in human ILC cell lines to assess the role of FADD in cell proliferation, cell cycle progression, cell survival and suppression of autophagy. In addition, I will perform functional experiments to assay the requirement for FADD in cell adhesion, migration and invasion. Aim 2: Characterize the non-canonical FADD signaling axis in ILC cell lines FADD translocates to the nucleus upon phosphorylation at Serine 194 by CK1? and FIST/HIPK3 kinases, leading to downstream activation of NF-?B and mTOR pathways. To dissect this FADD signaling cascade, I will combine genetic manipulation via RNAi and CRISPR with pharmacological inhibitors. In addition, I will identify ILC-specific components of this cascade through RNA-Sequencing, protein arrays and Mass Spectrometry approaches. Aim 3: Determine the prognostic and therapeutic significance of FADD in ILC tumors and explants This aim will initiate translation of this project toward clinical application. I will assay FADD and phosphorylated-FADD protein expression and correlate with clinical outcome in human ILC samples. Using innovative ex vivo tumor explants and novel xenograft mouse models of human ILC cell lines, I will evaluate the anti-tumor and anti-metastatic effects of genetic and pharmacological inhibitors of the FADD signaling axis combined with endocrine therapy. Career Development, Goals and Environment: This research project will be carried out under close guidance of my mentor Dr. Steffi Oesterreich, an international leader in ILC research, and in frequent interactions with clinicians, pathologists, patient advocates and biostatisticians, which will provide me with a unique, well-rounded training opportunity. Collaborations with Dr. Alnawaz Rehemtulla and Dr. Lukas Dow will provide a critical experience on the non-canonical FADD signaling pathway and genetic editing via CRISPR, which has not previously been a component of my training. While ensuring successful execution of the research aims in this proposal, this training will also provide a unique direction for my independent research career. The dedicated guidance I will receive from my mentor and my advisory committee, combined with the educational and career development opportunities at the University of Pittsburgh, will help me leverage my strengths into obtaining a junior faculty position as a translational breast cancer researcher at a top-tier academic institution to impact patient care.